Author: Danilo

Working with RPM Software Packages explains how Red Hat and other sources provide software as RPM packages, and investigates the installed system packages. First and foremost: What is an RPM Software Package? The RPM Package Manager, which Red Hat originally developed, provides a standard way to package software for distribution. Managing software in the form of RPM packages is simpler than working with software that is extracted to a file system from an archive. With RPM packages, administrators can track which files the software package installs, which files the software package removes if you uninstall it, and it verifies that supporting packages…

Gaining Superuser Access on RHEL shows how to access the system with superuser privileges. We’re using Red Hat Enterprise Linux; however, these examples apply to any Linux distribution. Most operating systems have a superuser (administrator) responsible for administrative and restrictive tasks. In the majority of Linux distributions, the superuser is the “root” account. For tasks such as installing or removing software, and to manage system files and directories, users must escalate their privileges to the root user. In some Linux distributions, for security purposes, the root account has no valid password by default, so we cannot directly log in as the root…

Working with Local Users and Groups on RHEL demonstrates how to manage Linux users and groups in a Linux system using the command line. All examples provided here are based on Red Hat Enterprise Linux 10; however, they should also work with any other Linux distribution. Linux Users A user account provides security boundaries between people and programs that can run commands. Users have usernames to identify them to human users and for ease of working. Internally, the system distinguishes user accounts by the unique identification number, the user ID (UID), which is assigned to them. In most scenarios, if a human uses…

Working with Shell Input and Output on RHEL aims to provide essential knowledge of standard input, standard output, and standard error on a Linux system. We’ll demonstrate how to manipulate each one and how to utilize it with pipelines to achieve a wide range of possible outcomes. All examples are run on Red Hat Enterprise Linux (RHEL); however, they apply to any Linux distribution. Standard Input (stdin), Standard Output (stdout), and Standard Error (stderr) A running program, or process, reads input and writes output. When we run a command from the shell prompt, it typically reads its input from the keyboard…

Edit Text Files from the Command Line on RHEL aims to provide essential knowledge of how to edit text files on Linux. We’re using Red Hat Enterprise Linux to provide the examples; however, you can use any Linux flavor for that. There are many text editors, so we’ll focus on “vim” in this article. What is Vim? Key Features of Vim Installing Vim As we mentioned earlier, Vim is already installed on most Unix/Linux systems. However, if necessary, installing Vim is a very straightforward task. With the vim-minimal package, you might install the vi editor with core features. This lightweight installation includes only the…

Matching File Names with Shell Expansions on RHEL shows what command-line expansions are and provides some usage examples. We’re using Red Hat Enterprise Linux 10, but all the examples apply to any Linux distribution. What are Command-Line Expansions? When we type a command at the Bash shell prompt, the shell processes that command line through multiple expansions before running it. We can use these shell expansions to perform complex tasks that would otherwise be difficult or impossible. The Bash shell can perform the following expansions: What “expansion” means: When you type a command, Bash scans the line for special patterns such as…